Does the glass production (raw, unpolished lenses) take place in Pentax own factories or do all camera manufacturers buy their raw lenses from a few big factories.
Most do. Minolta has (or had) its own factory though and, in the 60s, 70s and 80s at least, mentionned this in their booklets, adding that this way they had control over all aspects of lens making, from the silicium and rare earths to the finished products. We know that it does not give the lens maker more possibilities as ALL kinds of glass can be ordered from the diffrent glass makers around the world. I think Hoya is the biggest glass maker in Japan and there might not be more than one or two others in this country.
Interesting posts reading at:
http://medfmt.8k.com/mf/glassmfg.html
Andre
